Brantley

So I am having problems passing smog. I have taken it in 3 times with the following results,

For test 1, car completely stock, 75 degrees out...

Test 1 - %CO2 %O2 HC(PPM) CO(%) NO(PPM)
15 MPH 14.9 .3 Max 133 Meas 163 Max .82 Meas .30 Max 1125 Meas 948
25 MPH 15.1 .1 Max 108 Meas 99 Max .62 Meas .20 Max 955 Meas 449

Result - Failed HC @ 15 MPH - not by much!

For test 2, added 3 inch exhaust with newer catalytic converter, Vitesse AFM chip, 3.0 bar fpr, Accuboost boost controller, 100 degrees outside.

Test 2 - %CO2 %O2 HC(PPM) CO(%) NO(PPM)
15 MPH 13.3 .3 Max 133 Meas 263 Max .82 Meas .54 Max 1125 Meas 2300
25 MPH 14.0 .2 Max 108 Meas 105 Max .62 Meas .19 Max 955 Meas 533

Results - Failed HC and NO at 15 MPH and labled Gross Polluter! haha The car must have been running rich as it was smoking bad!

For test 3, I left the exhaust on, but removed the AFM chip and 3 bar fpr, 85 degrees outside. Results a little better, but still failed... not labeled gross polluter this time.

Test 3 - %CO2 %O2 HC(PPM) CO(%) NO(PPM)
15 MPH 11.5 3.5 Max 133 Meas 260 Max .82 Meas .47 Max 1125 Meas 1912
25 MPH 12.1 3.0 Max 108 Meas 105 Max .62 Meas .09 Max 955 Meas 210

One item to note is that I am running an octane boost in the gas for tests 2 and 3, would this make a difference?

After idling for a while, a grayish white smoke will build up. The smog tech thinks that the car is burning oil. Any truth to this? I haven't had the car for too long (4 months) but haven't noticed that I am burning oil. I just don't understand how the test results got so much worse so quickly.

Any help from other CA people would be appriciated.

Thanks,
Mike

sharky47

We don't have emissions testing in our area so I am kinda ignorant on this issue - when they test an older car, do they hold it to the standards at the time the car was made, or do you have to conform to current regs?

smac951

In CA. it's to current regs.

sharky47

So what happens when they set the standard so high that your car cannot pass no matter how well it is maintained?

docwyte

You turn the car into a race car.

mtnman82

Search is your friend on this. There was a thread not too long ago about smog problems, and in it was a link to a site with posible tuning problems based on emissions results. Did you get a SMT-6 with your Vitesse ship/board? You should be able to tune it out with this. I'm not sure why a 3" exhaust and new cat. would make the emissions worse. Sounds like it was running prety good to start with, and maybe just needed a new O2 sensor. Have you replaced that? You could always pay Home Depot a visit and get a couple gallons of xylene. I've read that is supposed to do the trick for emissions, but search on that too and use it carefully. Do the plugs look oily, or sooty??

PEvans

I have a little experience with this, and I think if you can't make the NO numbers it's the catalyst. You say "newer." How new? If the car is running right it seems like you should be able to make the HC numbers, but the NO may still be a problem with an old catalyst no matter how well the car is running.

A well maintained 951 with a replacement catalyst can comfortably pass CA smog.

rhesus

well all i have to offer is that i passed smog a few wks ago with the vitesse chips.

ibkevin

Wow, nice update, 367 days latter.

rhesus

eh?

ibkevin

Doh!

RK951

The most factual statement ever made on Rennlist.

Brantley

Well, after a year of tinkering and retesting the 951, I have finally passed the dreaded CA smog check. I have chronicled my repairs between smog checks in the below linked excel file. Hopefully, this may help others out there.

Couple of tips along the way I found helpful for my situation.

- Ask the smog shop what type of smog machine they are using. The 2 primary smog machines are 1. ESP or 2. SPX. Each time I took it to an ESP machine, it failed. The previous owner passed on a SPX machine, and I just passed on one today. Is this important? I don't know... Though, it worked for me.

- Keep the car idling prior to the test so that the catalytic converter stays HOT! Make sure to drive around 20 minutes before the test.

- The higher the RPMs during the 15 mph and 25 mph rolling test the better! Ask the smog tech to do the 15 mph test in 1st gear so the RPMs are higher. (Note, that the techs will get in trouble when using 1st gear as they are suppose to use 2nd).

- Used a fuel additive product called Blue Sky from blueskycleanair.com. This product claims to lower NO and some other improvements.

Below is the link to all the ugly details,

http://www.bids4gigs.com/smogtestprogress.xls

mtnman82

So which chips did you pass with? From the spreadsheet, looks like you found a few vacuum leaks ... maybe this in combination with the bad oxygen sensor (& maybe temp sensor) were the root cause? Just wondering your thoughts ...

Brantley

Passed with the stock DME chip. Though, when I added the vitesse chip (before 2nd check) verses when they were removed (before 3rd check), it made little difference. So, I believe that I could pass fine with the vitesse chip installed.

Well, the new cat really helped with the Hydro Carbons (HC). The tune up and new oxygen sensor helped with the Nitrous Oxide (NO). Then, what put me over the top was probably the vacuum leaks and fuel additive.